Red Supergiants -- The Other Side of the H-R Diagram

TL;DR

This paper reviews the properties, mass loss phenomena, and evolutionary significance of red supergiants, highlighting recent discoveries and ongoing questions about their final stages and circumstellar environments.

Contribution

It provides a comprehensive overview of red supergiants, emphasizing new insights into their mass loss episodes and evolutionary status, which are crucial for understanding massive star evolution.

Findings

Red supergiants exhibit high mass loss rates and episodic mass loss events.

Recent observations challenge existing models of their evolution and circumstellar environments.

Understanding their mass loss is key to predicting their final fate as supernovae.

Abstract

Red supergiants are the largest stars known with some of the highest mass loss rates observed. They are the final stage in the evolution of the majority of massive stars. The unexpected discovery of high mass loss episodes in many red supergiants have posed questions about the role of mass loss on their final stages. The papers in this volume are timely reviews of our current understanding of this often surprising population of massive stars. This introductory paper is a brief summary of their observed properties and a historical perspective on some of the current problems on mass loss, their circumstellar environments, and their evolutionary state.